docs: def delete(self, version_name):
      """Delete a version of model.
  
      Args:
        version_name: the name of the version in short form, such as "v1".
      """
      name = ('%s/versions/%s' % (self._full_model_name, version_name))
      response = self._api.projects().models().versions().delete(name=name).execute()
      if 'name' not in response:
        raise Exception('Invalid response from service. "name" is not found.')
      _util.wait_for_long_running_operation(response['name'])